In order to recognize a patient's disease, an examination involving X-ray irradiation by, for instance, an X-ray diagnosis apparatus and a CT (computed tomography) apparatus, is indispensable. However, while the examination involving X-ray irradiation provides an advantage that it may allow the disease of the patient to be recognized, the examination is also disadvantageous in the respect of exposing the patient to X-rays. Thus, it is important to manage the exposure dose of the patient from the standpoint of minimizing the exposure dose of the patient and understanding the risk of exposure damage.
Incidentally, the IEC (International Electrotechnical Commission) standards require measurement of CTDIw (weighted CT dose index) and DLP (dose-length product) for a CT apparatus, and require measurement of an incidence surface dose for an angiography apparatus.
On the other hand, radiation exposure damage first occurs on the skin. In order to understand the risk of such radiation exposure damage, it is necessary to manage the total dose of radiation exposure on the skin (skin exposure dose).
However, the skin exposure dose cannot be totally managed in one examination by such indices as CTDIw, DLP and incidence surface dose.
Meanwhile, there has been proposed an exposure dose management system in which a skin exposure dose in one examination using the angiography apparatus is integrated and displayed on a human body shape model (surface shape only).
However, in the above-described exposure dose management system, although the skin exposure dose in one examination can be managed, there is room for improvement as described below, according to the inventor's study.
In usual cases, a diagnosis and a medical treatment are not completed by a single examination. For example, a diagnosis and a medical treatment are completed after a plurality of steps, such as a diagnosis by a CT apparatus, a medical treatment by an angiography apparatus and a confirmation of an operation by the CT apparatus. Thus, the exposure dose management in one examination is not sufficient, and an exposure dose management corresponding to a plurality of times of X-ray irradiation becomes necessary.
In addition, it is known that the skin exposure dose recovers based on elapsed time during a plurality of times of X-ray irradiation, but the part that did not recover accumulates in the patient. Thus, if CT examinations are conducted today and tomorrow, the exposure dose accumulated after the examination of tomorrow becomes higher than the exposure dose accumulated after the examination of today. Therefore, it is necessary to manage the exposure dose accumulated by multiple times of X-ray irradiation.
However, in the conventional exposure dose management system, there is room for improvement in that the exposure dose accumulated by such multiple times of X-ray irradiation cannot be managed. Being able to manage such would be advantageous not only for the management of the skin exposure dose accumulated by X-ray irradiation, but also for the management of the exposure dose of internal organs with high sensitivity to exposure, such as the eye and thyroid gland. Further, the same applies to an exposure dose of an arbitrary region by an arbitrary radiation, such as an internal organ exposure dose accumulated by gamma ray irradiation. Specifically, in the conventional exposure dose management system, there is room for improvement in that the exposure dose accumulated by multiple times of irradiation cannot be managed.
The object is to provide an exposure dose management system which can manage an exposure dose accumulated by multiple times of irradiation.